Raikyn: ....
In regards to a big telephoto I might just get a 1.4 extender for my 400 f5.6 for now. What does that take the fstop down to? I'll have to check what my camera min fstop for autofocus is.....
I had a 1.4x extender and it was rubbish! I got clearer pictures expanding the photo's in PS and using noise ninja etc to tidy it up.
Perhaps there was a problem with the combination of my 40D, 70-200 f2.8L, the extender and me :)